Feed mechanism for grinding machines



A. a. BELDEN El AL 1,733,049

FEED MECHANISM FOR GRINDING MACHINES Oct 22, 1929.

2 Sheets- Sheet Filed April 9, 1927 AIberT G. Belden Joseph n. whiff/es Get 22, 1929. A. G. BELDEN ET AL 1,733,049

FEED IECHANISM FOR GRINDING IACHINES I I 2 Sheets-Sheet 2 Filed April 9, 1927 gwwntow Mum 44 5 38 A/berT G. Belden Joseph B.Whi1fles 9&1

Patented Oct. 22, 1929 ALBEn neQ B LnEN .AND JOSEPH. n we:

TILES, or; women-swan, MASSACHUSETTS, j

AssIenoRsf'ro'NORTONcoMPANY; or WORCESTER, MASSACHUSETTS, a conron rn Tron. or MASSACHUSETTS FEED MECHANISM FOR GRINDIIN G MACHINES Application filed April 9,

This. invention relates to cross feed mechanisms for grinding machines andmore particularly tQa power operated. cross feed in which the power is automatically disconnected-when the workhas been reduced to a predetermined size.

Heretofore variousmechanisms have been devised for feeding a grinding wheel by power tocause a relative'motion between the work and the grinding wheel to size the work.

In mechanisms of this type, itis essential that the power mechanism be disconnected whenthe work has been reduced to the desired size. Numerous mechanisms have been designed but have been of a more or less complicated construction and did not necessarily operate in timed relation with the stop for the feed mechanism unlesstheoperator made a fineadjustment and properly timed the power mechanism with the feeding and stopping mechanism.

Heretofore in grinding practice, it has been considered essential that the grinding wheel be permitted to grind-out or to permit the sparks to die-out after the feeding action has been stopped. This practice takes considerable time and is detrimental in modern grinding practice where it is essential to get the maximum production per machine. In production grinding practiceof today, itis considerednecessary for the grinding wheel to grind into the work to substantially reduce it in size. and then after the stop has been reached [to maintain the grinding wheel in contact with the work for a short period of time to finish grind the work.

It is one object of our invention to provide a powerfdriven cross feed mechanism with a positive throw. out or disconnection of the r power drive so that when the'feed mechanism comes into contact with the stop after the work has been reduced to the predetermined size, the'power will automatically be disconnectedj Heretofore, various of these mechanisms have been devised suchas that disclosed in the prior patent to Norton'No. 1,416,054; in which the power continues to turn the driving mechanism connected with the feed screw. Thesemechanisms are provided with a fricfollowing disclosure.

1927. .Serial No. 182,453.

tion clutch arrangement so that when the stop is-reached the power mechanism continues. to turn against-the friction of the disk-clutch This action continues until the operator man-- ually disconnects the power by throwinga hand lever. This construction is not efficient asthe continued use of the disk clutch and the power turning against the friction of the; disk wears the disk and necessitates frequent adjustments and replacement thereof,

- It is a further object of our invention to; overcome this objection, and to so construct and arrange the mechanism that when the feeding mechanism contacts with the stop,

after the work has been reduced to thedesired size the rolling action of the driving member automatically throws the gearing out of mesh and disconnects the power drive from the feedingmechanism. v o

It is a further object of our invention to construct and arran e the mechanism so that when the power has been disconnected the operator may manually throw the hand lever. in the opposite direction and connect a reverse feed to move the grinding wheel rearwardly away from the work by. power into an 3 inoperative position.

Other objects will be apparent from the =Referrin-g to the drawing in which like reference numerals indicate like parts;

Fig. I is a fragmentary front elevation of my power. driven feeding mechanism showingv the gearing in mesh to move the wheel toward j and into the work; I

Fig. 2 is a similar fragmentary view showing the power driving mechanismwith the;

gearing in proper relation to feed the grinding wheel has been sized;

Fig. 3is a fragmentary side elevation of.

-my power cross feed mechanism; and

away from'the work after the work Fig. etis a sectional. view of the-spring.

pressed plungers for holding the control lever in operative positions. In accordance with our invention, we. vide a feeding mechanism such as that shown in the prior patentto NortonN0.'1,4:1 6,054-'" with a positively driven clutch controlled power mechanism which is so constructed,

and arranged that when the feeding mechanism contacts with the stop, the positively driven mechanism will be automatically thrown out of gear without attention on the part of the operator.

As shown in the drawing, we have 1llustrated an improved mechanism adapted for use in connection with a feeding mechanism of the type disclosed in the patent to Norton, above referred to. This mechanism comprises a cross slide 11 adapted to slide on ways on the base of the machine (not shown). The slide carries a half nut 12 engaging a rotatable cross feed screw 13 which is mounted in any suitable hearings in the base of the machine. T 0 permit a fine feeding movement of the grinding wheel, relative to the work, we provide a reduction gearing so that a comparatively large amount of movement on the hand feed wheel 15 turns the feed screw only a small amount. The hand feed wheel 15 is mounted on a projection of the shaft 16 on the front of the machine base. The shaft 16 carries at its inner end a spur gear 17 meshing with a larger spur gear 18 on theshaft 19. The other end of the shaft 19'is provided with a pinion 2O meshing with a large gear 21 on the front end of the feed screw 13. By turning the hand feed wheel-15, the screw 1.3 is rotated to move the slide 11 in either direction.

To limit the motion of the wheel slide in one direction so that the work may be ground to a predetermined size, we provide a stop lever 23 adapted to be moved into the path of an abutment 24. The abutment 24 is car ried by the hand feed member 15 as is fully described in the prior patent to Norton. In order that the stop lever 23 may be thrown into the path of the abutment 24, we mount the spiral gear 25 on the shaft 16 meshing with a spiral gear 26 on the end of a screw 27.

The nut 28 engages the threads of the screw 27 and is held against rotation by a key 29 which slides in a keyway 30 in the member 31.

As the screw 27 is turned by movement of the hand feed wheel 15, the nut 28 which is held against rotation, slides longitudinally within the member 31. This movement continues until the nut 28 contacts with the projection 33 of the stop lever 23. Further feeding of the wheel moves the nut 28 toward the lef to swing the projection 33 and the stop lever 23 into the path of the abutment 24. This mechanism is not described in detail as it is not considered part of our present invention but for a detailed description reference may be had to the patent to Norton No. 1,416,054, above referred to. r

- To attain one of the objects of our invention, we provide a suitable power driven.

mechanism to rotate the cross feed screw, including a clutch having movable members so constructed and arranged that when the abutment 24 comes in contact with the stop lever movement of the movable clutch member to a certain point and then automatically withdraws the clutch, member and holds it out of contact with the otherclutch part until the operator manually moves them again into contact. Of the various types of clutch mechanism suitable for this purpose, we have illustrated a tumbler gear construction.

To this effect we provide a drive shaft 35 having a worm 36 meshing with a worm gear 37 mounted on a shaft 38. This shaft also carries a further gear 39. These gears are so arranged that when they are in mesh for a forward feed of the grinding wheel slide, they will be held in normal engagement by the. spring pressed plunger of the load and fire mechanism, but when the back pressure is too great, one of these gears will'be moved first by the back pressure and finally by the spring pressed load and fire mechanism to take it entirely out of contact with the other gear. As illustrated in the drawings, a tumbler gear 41 meshes with the gear 39 on shaft 38. The gear 41 is mounted on the stud 42 which is carried by the swinging arm 43. The arm 43 is integralwith a hub portion 44 and has a suitable bearing in the base of the machine (not shown). The gear 41 is positioned and arranged so that it may be thrown into mesh with the gear 18 to turn the feed screw 13 and produce a forward feeding movement to the grinding wheel.

To control the movement of the tumbler gear 41, we provide a manually operable lever 46 mounted on the outer end of the portion 44. Movement of the lever 46 toward the left, throws the tumbler gear 41 into mesh with the gear 18 to connect the power feeding mechanism to turn the feed screw and move the wheel slide toward and into the work. This motion continues until the work has been reduced to the desired size and the stop lever 23 is moved into the path of the abutment 24. When the abutrotation by the stop, automatically rolls the tumbler gear out of mesh with the gear 18, thereby disconnecting the power drive.

To hold the tumbler gear 41 in mesh, we

Imay provide any suitable means such as a spring pressed plunger 49 having the arrow point projections 50 and 51 adapted to engage a projection 52 on the lever 46. This i be fed rearwardly spring pressed plunger is so positioned that the operator may manually throw the lever 46 toward the left and move the tumbler gear 41 into mesh with the gear 18 by forcing the projection 52 of the lever across the face of the arrow point 50. The tension of the spring within the plunger is preferably suflicient to maintain the tumbler gear in mesh under the normal grinding thrusts but is such that it will yield and permit the lever 46 to be automatically thrown out by the rolling action of the tumbler gear 41 when the stop has been reached.

In order that the grinding wheel slide may after the completion of grinding, We provide a second gear 54 mounted on the stud 42 meshing with an intermediate gear 55 on the stud 56. This stud 56 also carries the second tumbler gear 57 fixed relative to the gear 55. The tumbler gear 57 is adapted to be thrown into mesh with a gear 58 on the outer end of the shaft 19. When it is desired to move the grinding wheel rearwardly out of contact with the work after a piece of work has been finish ground, the operator throws the lever 46 into its right hand position forcing it over the arrow point 51 of the spring pressed plunger 49, thereby throwing the tumbler gear 57 into mesh with the gear 58 to turn the feed screw 13 in the opposite direction and move the cross slide rearwardly. By utilizing the intermediate gear 55 a change in direction of motion is obtained. By a reduction in the mechanism a rapid motion is obtained to remove the grinding wheel rapidly to its inoperative position.

To prevent the tumbler gear 57 from being thrown into mesh with the gear 58 when the stop is reached, we provide a second arrow point 51 on the spring pressed plunger 49 which is positioned to limit the movement of the hand lever 46 and to prevent the gear 57 from meshing with the gear 58 until the operator manually forces the lever so that the projection 52 passes over the arrow point 51.

Vi hen the grinding wheel has moved rearwardly through the desired distance the operator may stop the feed by moving the lever 46 toward the left until the projection 52 passes over the arrow point 51 of the spring pressed plunger 49 to throw the tumbler gear 57 out of mesh. The tumbler gears are now in a neutral position to permit replacement of the work.

The operation of our mechanism is readily apparent from the foregoing disclosure. hen the work has been placed in the machine, the operator moves the lever 46 toward the left (as-viewed in Figs. 1 and 2), thereby throwing the tumbler gear 41 into mesh with the gear 18 to give a forward feeding movement to the wheel slide. The lever 46 is held in its left hand position by the proi ct en,52 ,engagi g,an ar ow. point 0 on the.

pr g pre ed plung r 49.71111e forward feed ofthe-wheeL slide continues untilthe stop lever 23 is: automatically thrown into the path of the abutment 24 to stop further feeding movement. lVhen the abutment 24 contacts with the, stop lever 23gitprevents further turning of the feedscrew13.. The stop holds gearlSagainst rotation, so that continued rotation ofthe tumbler gear 41 (in the direction of arrow Fig. 1 rolls the gear out of mesh with gear 18, thereby moving tion 52 on the lever passes over the arrow point 50 and intoa neutral position, The

lever 46 ,t oward the right sothat the projecoperator may then throw the lever 46 toward the right untilthe projection 52'passes the arrow point 51to throw the tumbler gear 57 nt m sh it the the grinding wheel slide to rapidly move away, fromlthe work. Afterthe wheel slide has receded a suliicientdistance the operator throws the lever 46 toward the left until projection 52passes over arrow point 51 into the neutral position.

We claim I 1.;A cross feed mechanism for grinding machines.comprising a slide, a half nut; on

said slide,across feed screw engaging saidnut, a tumbler gear mechan sm having two sets of positivelydriven gears, one for forward feed and onefor reverse feed, manual means to connectsaid tumblergear with said screw to move the slide in either direction, and a load and fire mechanism including yieldable means to hold said tumbler gear in or outof driving connection with the feed screw. during the normal thrust of grinding.

2. A cross feed mechanism for grinding machines comprising a slide, manual means includinga feed screw to movethe slide in either direction, a stop to limit the motion of said manual meansin one direction, a positively driven gear mechanism, including two relatively, movablegears connected with the screw. and so arranged that rotation in that direction which renders the stop effective tends to move the gears out of mesh, manual means to connect said gears to rotate the screw and yieldable means to hold said gears in connected position untilsthe stop operates to prevent further movement of the slide and thereafter permit them to roll out of I mesh;

,3. A cross feed mechanism for grinding machines comprising aslide, a nut on said slide,;a crossifeed screwengaging said nut, a stop to limit the rotationof said feed screw in one direction, atumbler gear mechanism having two sets of positively driven gears,

one forforward feed and one. for reverse feed,

manual means to connect said tumbler gears to rotate sa d screw to move the slide in either-,dire ction,isaid forward feed gears being so arranged that" they and to roll out of gear 58and thereby cause V feed screw in one mesh when driven, a load and fire mechanism including a spring pressed plunger arranged to hold said forward feed gears in mesh to rotate the feed screw during the grinding operation but arranged to permit said gears to automatically roll out of mesh when the feed mechanism contacts with the stop.

4:.- A cross feed mechanism for grinding machines comprising a slide, a nut on said slide, a rotatable cross feed screw engaging said nut, a stop to limit the rotation of said direction, a tumbler gear mechanism having two sets of positively driven gears, one for forward feed and one for reverse feed, manual means to connect said tumbler gears to rotate said screw to move the slide in either direction, said forward feed gears being so arranged that they tend to roll out of mesh when driven, and a load and fire mechanism including a spring pressed plunger having an arrow point projection arranged to hold said forward feed gears in mesh to rotate the feed screw during the grinding operation but arranged to permit said forward feed gears to automatically roll out of mesh when the feed mechanism contacts with the stop and a second arrow point arranged to hold the reverse feed gears in mesh to rotate the feed screw in the reverse direction.

5. A cross feed mechanism for grinding machines comprising a slide, a cross feed screw connected to move said slide, a stop arranged to limit the rotation of the feed screw in one direction, power mechanism including a clutch connected to said screw to rotate the same in said direction and a load and fire mechanism for holding the clutch in or out of engagement, said clutch comprising two relatively movable parts having engaging surfaces so arranged that the back pressure caused by stopping the feed screw automatically moves the clutch members out of engagement.

6. A cross feed mechanism for grinding machines comprising a slide, a cross feed screw connected to move said slide, a stop arranged to limit the rotation of the feed screw in one direction, power mechanism including a clutch connected to said screw to rotate the same in said direction and a load and fire mechanism for holding the clutch in Or out of engagement, said clutch having two gears normally in mesh which are mounted for relative movement and are so arranged that the back pressure set up by stopping the screw will automatically force the gears out. of mesh and operate the load and fire mechanism to hold the clutch out of engagement.

Signed at Worcester, Massachusetts, this 8th day of April, 1927.

ALBERT G. BELDEN. JOSEPH R. WHITTLES. 

